1. Field of the Invention
The present invention relates to an automatic opening/closing apparatus such as an electrically-operated sliding door and an electrically-operated sunroof which are used in a vehicle.
2. Description of the Related Art
Among vehicles such as wagons and vans, a type of vehicle is known which adopts a so-called sliding door in which a door panel is opened or closed by being slid in the longitudinal direction of the vehicle.
Among such sliding doors, there is an automatic sliding door apparatus whose opening/closing operation (i.e., the sliding of the door panel) is automated by the driving force of a driving means such as a motor, and which permits an occupant in the driver's seat to perform the opening/closing operation of for example, the door panel beside a rear seat.
In the conventional automatic sliding door apparatus, the detection of the nipping of a foreign object in a case where the door panel has nipped a foreign object at the time of closing the door panel is effected by detecting an overload of a motor accompanying a decline in the sliding velocity of the door panel which occurs due to the nipping of the foreign object by the door panel.
However, in ordinary automatic sliding door apparatuses, the sliding velocity of the door panel is delayed immediately before the full opening or full closing of the door panel so as to prevent vibration and noise during the opening or closing and improve the durability of a weatherstrip and the like provided at the door panel. Since the sliding velocity of the door panel changes immediately before the full opening or full closing of the door panel, the detection of the nipping of a foreign object is impossible in that portion of the opening or closing process. Accordingly, in this portion where the sliding velocity changes, mask processing is generally provided in which even if an overload of the motor is detected, a determination is made that the nipping of a foreign object by the door panel has not occurred, and the region where the sliding velocity of the door panel changes is set as a dead zone. For this reason, if a thin foreign object or a foreign object having a small shape is nipped, it is difficult to detect the nipping.
In addition, when the sliding door apparatus is made to undergo an opening/closing operation in a state in which the vehicle is inclined forward or backward, since the opening/closing velocity of the door panel changes due to the effect of gravity, there is a problem in that it is difficult to ascertain whether or not a foreign object has been really detected by the detection of an overload of the motor in such a case.